1. Field of the Invention
The present invention relates to a coil spring assembly and a damper mechanism having coil springs for absorbing vibrations in a clutch disc assembly of a frictional clutch mechanism or the like, and more particularly to a structure in which seat members are disposed at end portions of the coil springs.
2. Description of the Related Art
In a clutch disc assembly of an automotive frictional clutch mechanism, an input member and an output member are connected to each other in a clutch rotational direction by a damper mechanism. In one such damper mechanism, there is a coil spring assembly having several coil springs. Each end of each coil spring is provided with a seat member.
During a clutch disc assembling process for such a coil spring assembly, the seat members are mounted to the coil springs prior to assembly of the clutch disc assembly. The coil spring assembly is assembled along with other parts of the clutch disc as a single coil spring assembly. With such an arrangement, in the clutch disc assembling process, it is easy to handle each coil spring assembly to thereby simplify the assembling work.
However, in most assembling processes, the seat members are mounted onto the ends of the coil springs by temporary bonding in advance. Namely, the seat members are fixed to the coil springs by a weak adhesive so that the seat members are not separated from the coil springs during the assembling of the clutch disc.
In this case, in the work for mounting the seat members to the coil springs, the process for applying the adhesives to the seat members is required as an independent process, which leads to the increase of the steps. Also, there is a fear that the hardened adhesives might subsequently fly or otherwise be separated from the seat members and the coil spring during the operation of the clutch. The stiffened adhesives would adhere to the respective parts of the clutch and adversely affect the operation or the mechanical strength of the respective parts of the clutch such as coil springs.